RESONANCE RAMAN-SPECTRA OF PHTHALOCYANINE MONOLAYERS ON DIFFERENT SUPPORTS - A NORMAL-MODE ANALYSIS OF ZINC PHTHALOCYANINE BY MEANS OF THE MNDO METHOD

Resonance Raman spectra of monolayers of transition metal phthalocyani nes reveal specific interaction with the support. To elucidate its mec hanism, Raman spectra of zinc phthalocyanine monolayers were studied. The analysis was based largely on the results of MNDO calculations. Ca lculated wavenumbers turned out to be in good agreement with the exper imental results. It seems plausible that the alpha-nitrogen atoms domi nate the interaction with the support. Calculation results also show t hat the usually assumed D-4h geometry does not represent the true ener gy minimum but must be considered as the 'mean' of two mesomeric forms .